Planking is widely used in furniture. Various plankings exist nowadays and the main factors of planking chosen are its strength and weight. Traditional wooden or matchwood planks have the following shortcomings:
1. It needs a large amount of wood and thus the forest will be seriously destroyed.
2. Its processing procedure is complicated and it is difficult to be variational shaped. The quality and function arc easily affected by moisture and temperature.
Because of the shortcomings mentioned above, traditional wooden or matchwood planks are adopted less.
More and more plastic composite boards are used in furniture such as “a new model of the composite board and its process” issued by No. 02135460.X in China patent. The composite board is composed of honeycomb-core plate, foamed plastics and embedded components. The honeycomb-core plate is composed of honeycomb-core paper, surface paper and bottom paper. The honeycomb-core paper is placed non-stuckly between the surface plate and bottom plate; and the foamed plastics cover or partially cover the outside of the honeycomb-core plate and embedded components. The honeycomb-core plate, embedded components and foamed plastics form a unit.
Again, “a kind of composite board” issued by No. 02268887.0 in China patent is composed of the surface plate, bottom plate, honeycomb-core paper and foamed plastic. The surface and bottom plates are straight-formed plastic plates by means of blow molding or heat pressing. The honeycomb-core paper is placed between the surface and bottom plates. The edge of the surface plate and its corresponding one of the bottom plate are joined fixed hermetically by ultrasound weld or gluing. The foamed plastics fill the gaps among the honeycomb-core plate, surface plate and bottom plate.
Again, “a versatile absorptive honeycomb-core composite board”, issued by No. 200320016050 in China patent, includes the composite board and edging connecting fittings. The composite board includes the bottom plate, surface plate and honeycomb-core plate; the honeycomb-core plate is stuck between the surface and the bottom plates; the edging connecting fittings, used as the strengthening supported frame and as the connecting fittings for the composite board, cover the edge or partial edge of the honeycomb-core plate. The overlaps between the edging connecting fittings and the surface and bottom plates are connected by means of sticking or welding.
The plastic composites board mentioned above have the following shortcomings:
1. The strength of the board is not strong; the bottom and surface plates are independent components and they are connected by means of sticking and thus the connection is not stable. Moreover, the foamed plastics are not stuck to the bottom and surface plates, which reduces the strength of the board.
2. The weight of the board is not light efficiently. Because of the weights of the plastic plate, bottom plate and embedded components, the whole unit becomes heavy and is difficult for transportation and carrying.
3. The process of the board is more complicated and it needs specific devices of blow molding and suction molding.
4. As a result of the limit of the process, it is hard to form various shapes.